<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Data Change Notification Callbacks</title>
<style type="text/css">
body {
    margin: auto;
    font-family: Verdana, sans-serif;
    padding: 8px 1%;
}

a { color: #044a64 }
a:visited { color: #734559 }

.logo { position:absolute; margin:3px; }
.tagline {
  float:right;
  text-align:right;
  font-style:italic;
  width:300px;
  margin:12px;
  margin-top:58px;
}

.toolbar {
  text-align: center;
  line-height: 1.6em;
  margin: 0;
  padding: 0px 8px;
}
.toolbar a { color: white; text-decoration: none; padding: 6px 12px; }
.toolbar a:visited { color: white; }
.toolbar a:hover { color: #044a64; background: white; }

.content    { margin: 5%; }
.content dt { font-weight:bold; }
.content dd { margin-bottom: 25px; margin-left:20%; }
.content ul { padding:0px; padding-left: 15px; margin:0px; }

/* rounded corners */
.se  { background: url(../images/se.gif) 100% 100% no-repeat #044a64}
.sw  { background: url(../images/sw.gif) 0% 100% no-repeat }
.ne  { background: url(../images/ne.gif) 100% 0% no-repeat }
.nw  { background: url(../images/nw.gif) 0% 0% no-repeat }

/* Things for "fancyformat" documents start here. */
.fancy img+p {font-style:italic}
.fancy .codeblock i { color: darkblue; }
.fancy h1,.fancy h2,.fancy h3,.fancy h4 {font-weight:normal;color:#044a64}
.fancy h2 { margin-left: 10px }
.fancy h3 { margin-left: 20px }
.fancy h4 { margin-left: 30px }
.fancy th {white-space:nowrap;text-align:left;border-bottom:solid 1px #444}
.fancy th, .fancy td {padding: 0.2em 1ex; vertical-align:top}
.fancy #toc a        { color: darkblue ; text-decoration: none }
.fancy .todo         { color: #AA3333 ; font-style : italic }
.fancy .todo:before  { content: 'TODO:' }
.fancy p.todo        { border: solid #AA3333 1px; padding: 1ex }
.fancy img { display:block; }
.fancy :link:hover, .fancy :visited:hover { background: wheat }
.fancy p,.fancy ul,.fancy ol { margin: 1em 5ex }
.fancy li p { margin: 1em 0 }
/* End of "fancyformat" specific rules. */

</style>
  
</head>
<body>
<div><!-- container div to satisfy validator -->

<a href="../index.html">
<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite Logo"
 border="0"></a>
<div><!-- IE hack to prevent disappearing logo--></div>
<div class="tagline">Small. Fast. Reliable.<br>Choose any three.</div>

<table width=100% style="clear:both"><tr><td>
  <div class="se"><div class="sw"><div class="ne"><div class="nw">
  <table width=100% style="padding:0;margin:0;cell-spacing:0"><tr>
  <td width=100%>
  <div class="toolbar">
    <a href="../about.html">About</a>
    <a href="../sitemap.html">Sitemap</a>
    <a href="../docs.html">Documentation</a>
    <a href="../download.html">Download</a>
    <a href="../copyright.html">License</a>
    <a href="../news.html">News</a>
    <a href="../support.html">Support</a>
  </div>
<script>
  gMsg = "Search SQLite Docs..."
  function entersearch() {
    var q = document.getElementById("q");
    if( q.value == gMsg ) { q.value = "" }
    q.style.color = "black"
    q.style.fontStyle = "normal"
  }
  function leavesearch() {
    var q = document.getElementById("q");
    if( q.value == "" ) { 
      q.value = gMsg
      q.style.color = "#044a64"
      q.style.fontStyle = "italic"
    }
  }
</script>
<td>
    <div style="padding:0 1em 0px 0;white-space:nowrap">
    <form name=f method="GET" action="http://www.sqlite.org/search">
      <input id=q name=q type=text
       onfocus="entersearch()" onblur="leavesearch()" style="width:24ex;padding:1px 1ex; border:solid white 1px; font-size:0.9em ; font-style:italic;color:#044a64;" value="Search SQLite Docs...">
      <input type=submit value="Go" style="border:solid white 1px;background-color:#044a64;color:white;font-size:0.9em;padding:0 1ex">
    </form>
    </div>
  </table>
</div></div></div></div>
</td></tr></table>
<div class=startsearch></div>
  
<a href="intro.html"><h2>SQLite C Interface</h2></a><h2>Data Change Notification Callbacks</h2><blockquote><pre>void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);
</pre></blockquote><p>
The sqlite3_update_hook() interface registers a callback function
with the <a href="../c3ref/sqlite3.html">database connection</a> identified by the first argument
to be invoked whenever a row is updated, inserted or deleted.
Any callback set by a previous call to this function
for the same database connection is overridden.</p>

<p>The second argument is a pointer to the function to invoke when a
row is updated, inserted or deleted.
The first argument to the callback is a copy of the third argument
to sqlite3_update_hook().
The second callback argument is one of <a href="../c3ref/c_alter_table.html">SQLITE_INSERT</a>, <a href="../c3ref/c_alter_table.html">SQLITE_DELETE</a>,
or <a href="../c3ref/c_alter_table.html">SQLITE_UPDATE</a>, depending on the operation that caused the callback
to be invoked.
The third and fourth arguments to the callback contain pointers to the
database and table name containing the affected row.
The final callback parameter is the <a href="../lang_createtable.html#rowid">rowid</a> of the row.
In the case of an update, this is the <a href="../lang_createtable.html#rowid">rowid</a> after the update takes place.</p>

<p>The update hook is not invoked when internal system tables are
modified (i.e. sqlite_master and sqlite_sequence).</p>

<p>In the current implementation, the update hook
is not invoked when duplication rows are deleted because of an
<a href="../lang_conflict.html">ON CONFLICT REPLACE</a> clause.  Nor is the update hook
invoked when rows are deleted using the <a href="../lang_delete.html#truncateopt">truncate optimization</a>.
The exceptions defined in this paragraph might change in a future
release of SQLite.</p>

<p>The update hook implementation must not do anything that will modify
the database connection that invoked the update hook.  Any actions
to modify the database connection must be deferred until after the
completion of the <a href="../c3ref/step.html">sqlite3_step()</a> call that triggered the update hook.
Note that <a href="../c3ref/prepare.html">sqlite3_prepare_v2()</a> and <a href="../c3ref/step.html">sqlite3_step()</a> both modify their
database connections for the meaning of "modify" in this paragraph.</p>

<p>The sqlite3_update_hook(D,C,P) function
returns the P argument from the previous call
on the same <a href="../c3ref/sqlite3.html">database connection</a> D, or NULL for
the first call on D.</p>

<p>See also the <a href="../c3ref/commit_hook.html">sqlite3_commit_hook()</a> and <a href="../c3ref/commit_hook.html">sqlite3_rollback_hook()</a>
interfaces.
</p><p>See also lists of
  <a href="objlist.html">Objects</a>,
  <a href="constlist.html">Constants</a>, and
  <a href="funclist.html">Functions</a>.</p>
